STL Loader

2026-04-13 11:41:51 -05:00
parent 2b9ee8f721
commit c8abd374fe
8 changed files with 198 additions and 47 deletions
@@ -0,0 +1,120 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "asset/loader/display/assetmeshloader.h"
+#include "asset/asset.h"
+#include "assert/assert.h"
+#include "util/endian.h"
+#include "util/memory.h"
+
+errorret_t assetMeshLoader(assetfile_t *file) {
+  assertNotNull(file, "Asset file cannot be null");
+  
+  assetmeshoutput_t *output = (assetmeshoutput_t *)file->output;
+  assertNotNull(output, "Output cannot be null");
+  assertNotNull(output->outMesh, "Output mesh cannot be null");
+  assertNotNull(output->outVertices, "Output vertices cannot be null");
+
+  // STL file loading
+  errorChain(assetFileOpen(file));
+
+  // Skip the 80 byte header
+  errorChain(assetFileRead(file, NULL, 80));
+  if(file->lastRead != 80) errorThrow("Failed to skip STL header");
+
+  uint32_t triangleCount;
+  errorChain(assetFileRead(file, &triangleCount, sizeof(uint32_t)));
+  if(file->lastRead != sizeof(uint32_t)) errorThrow("Failed read tri count");
+  // normalize
+  triangleCount = endianLittleToHost32(triangleCount);
+  
+  // Allocate mesh and vertex data
+  errorret_t ret;
+  meshvertex_t *verts = memoryAllocate(
+    sizeof(meshvertex_t) * triangleCount * 3
+  );
+  *output->outVertices = verts;
+
+  // Read triangle data
+  for(uint32_t i = 0; i < triangleCount; i++) {
+    assetmeshstltriangle_t triData;
+    ret = assetFileRead(file, &triData, sizeof(triData));
+    if(ret.code != ERROR_OK) {
+      memoryFree(verts);
+      errorChain(ret);
+    }
+
+    if(file->lastRead != sizeof(triData)) {
+      memoryFree(verts);
+      errorThrow("Failed to read triangle data");
+    }
+
+    // Skip normals, we don't use them
+
+    // Fix endianess of of data
+    for(uint8_t j = 0; j < 3; j++) {
+      verts[i * 3 + j].color.r = (uint8_t)(endianLittleToHostFloat(
+        triData.normal[0]
+      ) * 255.0f);
+      verts[i * 3 + j].color.g = (uint8_t)(endianLittleToHostFloat(
+        triData.normal[1]
+      ) * 255.0f);
+      verts[i * 3 + j].color.b = (uint8_t)(endianLittleToHostFloat(
+        triData.normal[2]
+      ) * 255.0f);
+      verts[i * 3 + j].color.a = 0xFF;
+        
+      verts[i * 3 + j].uv[0] = 0.0f; // No UV data in STL, just set to 0
+      verts[i * 3 + j].uv[1] = 0.0f;
+
+      for(uint8_t k = 0; k < 3; k++) {
+        verts[i * 3 + j].pos[k] = endianLittleToHostFloat(
+          triData.positions[j][k]
+        );
+      }
+
+      // Convert Z-Up to Y-Up
+      float_t temp = verts[i * 3 + j].pos[1];
+      verts[i * 3 + j].pos[1] = verts[i * 3 + j].pos[2];
+      verts[i * 3 + j].pos[2] = temp;
+    }
+  }
+
+  // Finally, init mesh
+  ret = meshInit(
+    output->outMesh,
+    MESH_PRIMITIVE_TYPE_TRIANGLES,
+    triangleCount * 3,
+    verts
+  );
+  if(ret.code != ERROR_OK) {
+    memoryFree(verts);
+    errorChain(ret);
+  }
+
+  ret = assetFileClose(file);
+  if(ret.code != ERROR_OK) {
+    errorCatch(errorPrint(meshDispose(output->outMesh)));
+    memoryFree(verts);
+    errorChain(ret);
+  }
+
+  errorOk();
+}
+
+errorret_t assetMeshLoad(
+  const char_t *path,
+  mesh_t *outMesh,
+  meshvertex_t **outVertices
+) {
+  assertNotNull(path, "Path cannot be null");
+  assertNotNull(outMesh, "Output mesh cannot be null");
+  assertNotNull(outVertices, "Output vertices cannot be null");
+  
+  assetmeshoutput_t output = { outMesh, outVertices };
+  return assetLoad(path, &assetMeshLoader, NULL, &output);
+}